For the purpose of achieving as light a weight as possible, custom-made components, which are differently dimensioned as a function of the localised load to be expected in their later service and are joined together, are used in the automotive industry but also in other technical fields. In particular so-called “tailored tubes”, which are specially adapted to the different loads and must be joined together to form the support, are used as supports in the automotive industry. The method for producing such hollow profiled elements consists of butt-welding together blanks from a metallic material of various thickness and then shaping these into the hollow profiled element. In order to improve the lightweight construction method it is known from German Patent DE 100 38 337 A1 to join stiffening and/or functional elements onto a planar blank made of sheet metal and to shape the resulting blank into a hollow profiled element. For this purpose the stiffening and/or functional element must be produced separately from the blank and shaped accordingly before it is joined onto the blank, so that a further reduction in the process steps for producing hollow profiled elements, designed to meet load requirements, would be desirable.
Stiffening and/or functional elements are generally understood to mean brackets, hoops, flanges etc., which on the one hand, for example, are used for connecting other hollow profiled elements, so-called flange or connection elements. On the other hand, for example, brackets bent around 180° can also form stiffening elements by formation of an area with double the thickness of the blank.
German Patent DE 103 58 502 B3 furthermore discloses a method for producing a hollow profiled element, by means of which a connection element to join a further component is introduced into a hollow profiled element to be coiled up. The introduction of the connection elements however is to take place in a pre-formed area of the hollow profiled element, in order to ensure the dimensional precision of the connective opening that has been introduced. Because in this method the connection elements are shaped from a preformed area of the blank, this however still has residual bends. The distance between the areas of the connection elements to be joined together varies due to the residual bends. Thus the prior art connection elements do not ensure ideal joining conditions, so that reliability of the process is reduced when different hollow profiled elements are joined together.